This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Fengshan Liu Analysis of 3D Breast Surface Deformation during Mammographic Compression Mammography is the standard clinical imaging modality for screening asymptomatic women for early breast cancer. Breast compression, which is an essential part of the mammographic exam, causes deformation of the breast relative. It is important to account for this deformation when comparing breast images taken at different times, or images using various modalities. In this project we study the relationship between the breast surface deformation, surface force distribution, and the applied mammographic compression force, which is necessary for designing an improved breast positioning protocol aimed at achieving more comfort and less motion during mammography. This study could also be used for improving mammogram registration methods, and for refinement of breast tissue modeling and mammography simulation. The specific aims of this project include: 1. Development of a breast compression analysis system;2. Evaluation of the compression analysis system using physical phantoms;and 3. Pilot clinical study of breast deformation with 10-20 volunteers.